What is the circle that Earth’s axis traces out in its 26,000-year precession cycle? What bright stars would be close to it?

Tim Boyle, Nishinomiya, Japan

Published: Monday, July 23, 2012

Four thousand years ago, Egyptian astronomers were using the star Thuban (Alpha Draconis) as their pole star. Although it was never as close to the Celestial Pole as Thuban, Kochab (Beta [β] Ursae Minoris) served as the North Star around 2000 B.C. About 1,000 years ago, people began using Polaris as a standard for navigation. Alas, Polaris too will slip away from the Celestial Pole. In 14,000 years, the brilliant star Vega (Alpha Lyrae) will replace it.

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